1. Field of the Invention
The embodiments discussed herein are related to a technology of drawing images by projecting three-dimensional objects from a plurality of viewpoints.
2. Description of the Related Art
In conventional handwritten animation and comic books, in order to give a strong realistic sensation or impact, in a perspective drawing method, expressions in which the difference in the visual size between a distant part and a close part is excessively exaggerated, are often used.
FIGS. 1A and 1B illustrate an example of comparing an exaggerated image with a regular image. Comparing FIG. 1A and FIG. 1B, in FIG. 1B, the foot 102 is drawn to appear larger than the foot 101 in FIG. 1A, and therefore the depth is clearly expressed and impressive. The image of FIG. 1A has been rendered by an accurate perspective projection method. Meanwhile, in the image of FIG. 1B, the depth expression is exaggerated by enlarging the difference in the visual size between the foot that is stuck out forward and the rest of the body. In the present specification, this kind of image is referred to as an “exaggerated image”.
For example, in a scene where an impact is needed, such as in robot animation or sports, expressions of extremely exaggerating the perspective have been often used. Such a flexible two-dimensional expression can be freely drawn by handwriting; however, in CG (computer graphics) video images constituted by camera parameters and 3D models, expressions may be difficult. Therefore, when combining a handwritten video image with a CG video image, the inconsistencies between the respective drawing methods may be revealed and a feeling that something is wrong in the image may be given.
There is a technology of reducing the disparity, by enlarging an object that is protruding out from the display surface of a 3D image (see, for example, Patent Document 1).
There is a technology of combining images from a plurality of viewpoints (cameras), and rendering the combined images on a two-dimensional plane (see, for example, Non-patent Document 1, Non-patent Document 2, Non-patent Document 3, Non-patent Document 4).    Patent Document 1: Japanese Laid-Open Patent Publication No. 2006-293792 (US2006/0232584 (A1))    Non-patent Document 1: CGWORLD.jp “New dynamics in Japanese animation CG” Autodesk 3ds Max 2011×PSOFT Pencil+3 (Fourth Part) http://cgworld.jp/feature/review/pencil+3-vol4.html    Non-patent Document 2: Multi-perspective Modeling, Rendering, and Imaging SIGGRAPH ASIA 2008 Course Note, http://www.csbio.unc.edu/mcmillan/pubs/siga08-yu.pdf    Non-patent Document 3: E-IMPACT ˜3DCG imitating exaggerated expressions in Japanese animations˜Feature•Latest digital content production technology, Video information media society academic journal, February 2012, 66(2), 102-105    Non-patent Document 4: “E-IMPACT: Exaggerated Illustrations using Multi-perspective Animation Control Tree Structure”, ACE 2011-International Conference on Advances in Computer Entertainment Technology and DIMEA 2011-Digital Interactive Media Entertainment and Arts Conference (Nov. 8-Nov. 11, 2011). http://d1.acm.org/citation.cfm?id=2071502